2.1 Introduction: Children are a critical population to study given the potential for changed brain development due to substance use. Substance use disorders are a pediatric disease and children deserve the same attention as adolescents and adults. This project will examine prospectively collected de-identified data from children receiving drug treatment to inform providers how children can be treated in the USA. In 2011, the Bureau of International Narcotics and Law Enforcement Affairs (INL) of the US Department of State supported the United Nations Office on Drugs and Crime (UNODC) in the development and implementation of an intervention focused on reducing substance use and improving outcomes for children. Dr. Hendree Jones, PI developed the protocols to treat substance use in children (ages 4-17). Results from the 700+ children treated with this early version of our Stopping Use of Narcotics: CHild Intervention to Lift Development (SUN CHILD) intervention indicated that children showed a consistent pattern of significant (all ps<.001) decreases from baseline to post-treatment assessment, with gains maintaining at follow-up in psychiatric disturbance, anxiety-related emotional disorders, social problems, and increases in quality of life. Design: The NIDA-supported part of this study will be to receive and analyze in the USA, the de-identified data from a parallel, two-group, randomized controlled trial in which substance-using (cannabis, solvents, or opioids as the primary drug of use) children 7-12 years of age entering residential treatment randomized to receive either the SUN CHILD intervention (n=272: 204 boys and 68 girls), or usual care (n=272: 204 boys and 68 girls), with the 3:1 male:female ratio of assignment to treatment representing the approximate prevalence of substance use in this population. Outcome assessment instruments will be administered at baseline, post-treatment, and 1-, 3-, 6-, and 12-month post-treatment follow-up. Directly comparing intervention conditions will begin to answer critical questions about the efficacy of reducing cannabis, solvent, and opioid use as well as other substance use and improving the well-being of children. Aims: The main aim is to determine the extent to which the SUN CHILD condition, relative to the usual care condition, shows for the two primary outcomes, (a) longer mean duration of treatment, and (b) greater reductions in mean use of psychoactive substances over the course of post-treatment and 1-, 3-, 6-, and 12-months post-treatment follow-up; and, for the six secondary outcomes, greater reductions in mean (c) HIV risk behaviors, (d) psychiatric disturbance, (e) anxiety-related emotional disorders, (f) social problems, (g) post-traumatic stress symptoms, and larger increases in mean (h) quality of life at post-treatment and 1-, 3-, 6-, and 12-months post-treatment follow-up. The ancillary aim includes understanding the extent to which SUN CHILD is differentially efficacious for (1) girls and boys, (2) younger children v. older children, and (3) examining the relative efficacy of SUN CHILD in children for whom cannabis, solvents, or opioids is the primary drug of choice. Goals: Proximal: To determine the efficacy of the SUN CHILD intervention in terms of the above noted outcomes. Distal: To develop an efficacious intervention to stop substance use among children.